Use-after-free in Linux kernel - CVE-2026-45995

Vulnerability identifier: #VU132487

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-45995

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use-after-free in io_free_rbuf_ring() when freeing a provided buffer ring after io_zcrx_ifq_free() has released the associated user_struct. A local user can trigger the affected io_uring zcrx cleanup path to cause a denial of service.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-raspi (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-27.27
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-nvidia (Ubuntu package) - update to 7.0.0-1013.13
linux-raspi (Ubuntu package) - update to 7.0.0-1014.14

• https://git.kernel.org/stable/c/0fcccfd87152f957fa8312b841f6efef42a05a20
• https://git.kernel.org/stable/c/9feb88eeda6d288f93fcfb6bca563f89e316479d

• Use-after-free in Linux kernel io_uring
• Ubuntu update for linux
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure